DEVICE FOR MAGNETIC FLAW DETECTION OF PUMP RODS Russian patent published in 2020 - IPC G01N27/83 G01N27/72 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, namely to flaw detection of rods by means of magnetic investigations during tripping operations. Device includes a downhole module and a diagnostic system comprising a cable, a selsyn fixed relative to the wellhead, which is a converter of roller rotation into an electrical signal, designed to measure movement, ground electronics unit including a power supply and a ground controller, as well as a personal computer connected in such a way that the well module is connected via a cable to a ground electronics unit and a personal computer connected via a standard interface. Downhole module comprises a magnetising device made in the form of a magnetic conductor with a magnetization coil, a magnetizing section of rods located between the magnetic conductor poles, to a condition close to "technical saturation" in the direction along the generatrix of the line of rods, main scanning magnetic system, made in the form of a series of magnetically sensitive sensors arranged on flexible "skis" between poles of the magnetic conductor, on-board controller installed in close proximity to the magnetizing device and the main scanning magnetometric system, each of data inputs of which is connected to output of corresponding magnetically sensitive sensor. Output of power supply is connected to inputs of magnetising device, corresponding magnetosensitive sensor and onboard controller, which output is connected to ground controller first input, connected by second input to selsyn output, and by output to PC, wherein each of the magnetically sensitive sensors is connected to the on-board controller through the sealed connector, which provides protection against corrosion action, excessive pressure, high temperature of water-oil medium and vibration, is fixed on a flexible "ski". Flexible "ski" is configured to move along surface of rods, and magnetization coil is placed in protective casing. Downhole module is made with possibility to install power rotor for rods rotation from above. Magnetic conductor is made in the form of a ring with annular ledges located at both ends inside and outside, is equipped with upper and lower dielectric dielectrics and is made with possibility to install and fix the well flange on the conductor well head. Magnetisation coil is located between external annular projections, and a number of sensors – between internal with pressing inside, wherein the selsyn roller and the flexible "skis" of the sensors are configured to interact with the outer surface of the riser from the well. Rods of extracted column can be equipped with individual visual and/or magnetic marks applied on external surface. Optical and/or magnetic data readers with visual and/or magnetic mark, respectively, connected to appropriate inputs of on-board controller can be installed on top of magnetic conductor along perimeter.

EFFECT: design of a device for magnetic flaw detection of pump rods at their descent or lifting from the well, which enables to compare defects from each specific bar (individualize).

1 cl, 4 dwg